Slug

7.3

The Slug constraint was introduced in Symfony 7.3.

Validates that a value is a slug. By default, a slug is a string that matches the following regular expression: /^[a-z0-9]+(?:-[a-z0-9]+)*$/.

Note

As with most of the other constraints, null and empty strings are considered valid values. This is to allow them to be optional values. If the value is mandatory, a common solution is to combine this constraint with NotBlank.

Applies to	property or method
Class	Slug
Validator	SlugValidator

Basic Usage

The Slug constraint can be applied to a property or a getter method:

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        // src/Entity/Author.php
namespace App\Entity;

use Symfony\Component\Validator\Constraints as Assert;

class Author
{
    #[Assert\Slug]
    protected string $slug;
}
    

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        # config/validator/validation.yaml
App\Entity\Author:
    properties:
        slug:
            - Slug: ~
    

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        <!-- config/validator/validation.xml -->
<?xml version="1.0" encoding="UTF-8" ?>
<constraint-mapping xmlns="http://symfony.com/schema/dic/constraint-mapping"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://symfony.com/schema/dic/constraint-mapping https://symfony.com/schema/dic/constraint-mapping/constraint-mapping-1.0.xsd">

    <class name="App\Entity\Author">
        <property name="slug">
            <constraint name="Slug"/>
        </property>
    </class>
</constraint-mapping>
    

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        // src/Entity/Author.php
namespace App\Entity;

use Symfony\Component\Validator\Constraints as Assert;
use Symfony\Component\Validator\Mapping\ClassMetadata;

class Author
{
    // ...

    public static function loadValidatorMetadata(ClassMetadata $metadata): void
    {
        $metadata->addPropertyConstraint('slug', new Assert\Slug());
    }
}
    

Examples of valid values:

foobar
foo-bar
foo123
foo-123bar

Uppercase characters would result in an violation of this constraint.

Options

`regex`

type: string default: /^[a-z0-9]+(?:-[a-z0-9]+)*$/

This option allows you to modify the regular expression pattern that the input will be matched against via the preg_match PHP function.

If you need to use it, you might also want to take a look at the Regex constraint.

`message`

type: string default: This value is not a valid slug

This is the message that will be shown if this validator fails.

You can use the following parameters in this message:

Parameter	Description
`{{ value }}`	The current (invalid) value

`groups`

type: array | string default: null

It defines the validation group or groups of this constraint. Read more about validation groups.

`payload`

type: mixed default: null

This option can be used to attach arbitrary domain-specific data to a constraint. The configured payload is not used by the Validator component, but its processing is completely up to you.

For example, you may want to use several error levels to present failed constraints differently in the front-end depending on the severity of the error.

This work, including the code samples, is licensed under a Creative Commons BY-SA 3.0 license.

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